Triazines reactions with organolithiums

Starting from the 1,3,5-triazines, few syntheses of dihydro-1,3,5-triazines have been reported. Although many versatile synthetic approaches are available, most of them are yet to be tried. The known reactions involve preparation of dihydro-1,3,5-triazine derivatives from 2,4,6-triphenyl-1,3,5-triazine (153) via (a) lithium aluminum hydride reduction264 (b) treatment with potassium in tetrahydrofuran, followed by hydrolysis265 and (c) reaction with organolithium compounds and hydrolysis266 [Eq. (81)]. 

Treatment of 1,2,4-triazine 22 with organolithium compounds results in the formation of adducts 23 (yields 8-18%), whereas the reaction of 22 with tert- mX - or -butyllithium as C-nucleophiles affords the hexahydrotriazine 24 (Scheme 15) <2002J(P1)2549>. 

On reaction with MeMgCl, the lithium triazine Li(TF[F)2 N[C(Ph)=N]2 CBut(Bun) yields the methylmagnesio-dihydrotriazine 86 (Equation (18)). An X-ray crystal structure determination revealed that the compound closely resembled its lithio precursor the formal substitution of MeMg+ (Mg-C = 2.164(3) A) for Li+ did not produce the substantial structural differences often observed between isoleptic organolithium and organomagnesium systems.267... 

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